Polyether polyols are used in the polyurethane industry for the production of polyurethane products such as coatings, sealants, adhesives, elastomers, and foams. The industrial production of polyether polyols generally involves two alternative reactions—either the base-catalyzed oxyalkylation of starter molecules or the double metal cyanide (DMC)-catalyzed oxyalkylation of starter molecules. The base and DMC catalysts used for the production of polyether polyols are incompatible because base catalysts deactivate DMC catalysts. Therefore, base-catalyzed polyol production and DMC-catalyzed polyol production generally require separate and dedicated production reactors to avoid cross-contamination of base compounds in DMC-catalyzed reaction mixtures. This can increase the cost of polyether polyol production and result in reactor under-utilization. An alternative is washing the reactor with polyol, solvent, water and/or an acidic solution when switching between base-catalyzed and DMC-catalyzed technologies in the same reactor. This creates significant waste from the wash that must be properly treated and disposed of, which increases production costs. The reactor must also be thoroughly dried to remove any trace solvent and/or water remaining in the reactor as these trace contaminants can decrease the activity of the DMC-catalyzed reaction and contribute to undesirable volatile organic compounds (VOCs) in the polyether product. Therefore, an improved process for switching between the base-catalyzed reaction and the DMC-catalyzed reaction is necessary.